After King's Landing was seized by the Lannister forces, she was found by Ser Amory Lorch hiding under the bed of her father Rhaegar. While Gregor Clegane killed her baby brother and mother, Lorch killed Rhaenys by stabbing her about fifty times. Even Tywin considered that deed overly brutal (not the murder itself, but the manner in which it was done). He asked Lorch why killing a four year old girl required so many thrusts, and Lorch answered that she kicked him and would not stop screaming. Tywin commented that if Lorch had half the brain a turnip has, he would have calmed Rhaenys with a few sweet words and used a soft silk pillow to smother her.